JP6648590B2 - Printing device, tension control method - Google Patents

Description

  The present invention relates to a technique for controlling a tension applied to a recording medium to be printed.

  2. Description of the Related Art Conventionally, a printing apparatus that performs printing on a recording medium while conveying the recording medium in a predetermined direction is known. Further, in such a printing apparatus, a control for appropriately changing the tension applied to the recording medium in accordance with the operation state is executed. For example, in Patent Literature 1, while the continuous paper is being conveyed, a desired tension is applied to the continuous paper at the time of printing, while at the time when the conveyance of the continuous paper is stopped, the control for reducing the tension of the continuous paper to the desired tension at the stop is performed. Be executed.

JP 2010-180042 A

  By the way, for example, some users may want to transport the recording medium again according to their own purpose after stopping the transport of the recording medium. On the other hand, if the tension of the recording medium is lowered when the conveyance is stopped as in Patent Literature 1, an appropriate tension may not be applied to the recording medium when re-conveying, and the recording medium may not be properly conveyed. Was.

  The present invention has been made in view of the above problems, and has as its object to provide a technique capable of appropriately conveying a recording medium in re-conveying the recording medium after the conveyance of the recording medium is stopped.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following aspects.

  According to a first aspect (printing apparatus) of the present invention, a transport unit that transports a recording medium while applying tension to the recording medium, a printing unit that prints an image on the recording medium, an input unit that receives a transport command, and a transport unit A first transport operation for transporting the recording medium by the unit, a stop operation for stopping the transport of the recording medium to the transport unit and terminating the first transport operation, and a transport operation when a transport command is input to the input unit after the stop operation. And a control unit capable of executing a second conveyance operation of conveying the recording medium by the unit. The control unit continues to execute the first conveyance operation until a predetermined period elapses from the stop operation. The first tension control for maintaining the tension constant and reducing the tension of the recording medium after a predetermined period has elapsed from the stop operation is executed.

  According to a second aspect (a tension control method) of the present invention, a step of performing a first transport operation for transporting a recording medium, and a step of performing a stop operation for stopping transport of the recording medium and terminating the first transport operation Performing a second transport operation for transporting the recording medium when a transport command is input after the stop operation, and continuously performing the first transport operation until a predetermined period elapses from the stop operation. The tension of the recording medium is kept constant, and the tension of the recording medium is decreased after a predetermined period has elapsed from the stop operation.

  In the present invention configured as described above (first aspect and second aspect), the first transport operation for transporting the recording medium is performed, and the transport of the recording medium is stopped to end the first transport operation. The operation is performed. Further, the tension of the recording medium is maintained constant from the execution of the first transport operation until a predetermined period elapses from the stop operation, and the tension of the recording medium is reduced after a predetermined period elapses from the stop operation. (First tension control). That is, the tension of the recording medium is not immediately reduced when the conveyance of the recording medium is stopped, but the tension of the recording medium is maintained at the tension during the first conveyance operation for a predetermined period after the conveyance of the recording medium is stopped. Therefore, if the timing at which the user inputs the transport command for re-transporting the recording medium is within this predetermined period, the re-transportation of the recording medium (second transport) is performed with the appropriate tension applied to the recording medium. Action). As a result, it is possible to appropriately convey the recording medium in the re-conveyance of the recording medium performed after the conveyance of the recording medium is stopped.

  Further, the control unit executes a first conveyance operation to execute a printing operation of printing an image on the recording medium by the printing unit while conveying the recording medium by the conveyance unit, and performs the first conveyance operation in response to the end of the printing operation. A stop operation is performed to end the operation. In the first tension control, the tension of the recording medium is maintained constant from the time of execution of the print operation until a predetermined period elapses from the stop operation, and the first tension control is performed. The printing apparatus may be configured to decrease the tension of the recording medium after a predetermined period has elapsed.

  In such a configuration, a printing operation for printing an image on the recording medium while the recording medium is being conveyed is executed, and a stop operation for stopping conveyance of the recording medium in response to the end of the printing operation is executed. Further, the tension of the recording medium is maintained constant from the execution of the printing operation until a predetermined period elapses from the stop operation, and the tension of the recording medium is reduced after a predetermined period elapses from the stop operation ( First tension control). That is, the tension of the recording medium is not reduced immediately when the conveyance of the recording medium is stopped, but the tension of the recording medium is maintained at the tension during the printing operation for a predetermined period after the conveyance of the recording medium is stopped. Therefore, if the timing at which the user inputs the transport command for re-transporting the recording medium is within this predetermined period, the re-transportation of the recording medium (the second transport Action). As a result, it is possible to appropriately convey the recording medium in the re-conveyance of the recording medium performed after the conveyance of the recording medium is stopped.

  Further, the control unit is configured to maintain the tension of the recording medium constant from the time of execution of the previous print operation until the next print operation is started after the end of the previous print operation, and The printing apparatus may be configured such that the first tension control can be selectively executed. Also in the second tension control, the recording medium can be re-conveyed in a state where an appropriate tension is applied to the recording medium. Therefore, in the re-conveyance of the recording medium performed after the conveyance of the recording medium is stopped, the recording medium can be appropriately conveyed.

  At this time, the control unit executes the first tension control when the magnitude of the tension applied to the recording medium at the time of performing the printing operation is equal to or more than a predetermined tension, and the magnitude of the tension applied to the recording medium at the time of performing the printing operation is reduced. The printing device may be configured to execute the second tension control when the tension is less than the predetermined tension. Accordingly, it is possible to suppress the recording medium from being stretched due to a large tension greater than or equal to the predetermined tension being applied to the stopped recording medium for a long time.

  Further, the control unit may be configured to configure the printing apparatus so as to determine which of the first tension control and the second tension control is to be executed according to the type of the recording medium. Thereby, appropriate tension control according to the type of the recording medium can be executed.

  Further, the control unit may be configured to configure the printing apparatus to determine which of the first tension control and the second tension control is to be executed according to the width of the recording medium. This makes it possible to execute appropriate tension control according to the width of the recording medium.

  The transport unit has a driving roller that drives the recording medium, and a support unit that is arranged to face the printing unit and supports the recording medium that is driven by the driving roller, and the recording medium that is supported by the support unit. The control unit adjusts the torque of the drive roller so that the first tension control can be performed on the recording medium supported by the support unit. The device may be configured. With such a configuration, the recording medium can be re-conveyed with an appropriate tension applied to the recording medium supported by the support portion. As a result, in the re-conveyance of the recording medium performed after the conveyance of the recording medium is stopped, it is possible to appropriately convey the recording medium while supporting the recording medium with the support unit.

  The transport unit has a winding shaft for winding the recording unit printed by the printing unit, and applies tension to the recording medium wound on the winding shaft by a torque of the winding shaft. The printing apparatus may be configured such that the first tension control can be performed on the recording medium supported by the winding shaft by adjusting the torque of the winding shaft. With such a configuration, it is possible to re-convey the recording medium in a state where an appropriate tension is applied to the recording medium supported by the winding shaft. As a result, in the re-conveyance of the recording medium performed after the conveyance of the recording medium is stopped, the recording medium can be appropriately conveyed while being supported by the winding shaft.

  Further, the printing apparatus is configured such that the tension of the recording medium supported by the support unit after performing the first tension control is greater than the tension of the recording medium supported by the winding shaft after performing the first tension control. Is also good. With this configuration, a certain amount of tension is applied to the recording medium supported by the support unit even after the execution of the first tension control. Therefore, it is possible to prevent the recording medium from floating from the support portion and coming into contact with the printing portion due to the decrease in tension.

  The transport unit has a feeding shaft for feeding the recording medium to the printing unit, and applies tension to the recording medium fed from the feeding shaft by the torque of the feeding shaft, and the control unit adjusts the torque of the feeding shaft. By doing so, the printing apparatus may be configured such that the first tension control can be performed on the recording medium supported by the feeding shaft. With this configuration, it is possible to re-convey the recording medium in a state where an appropriate tension is applied to the recording medium supported by the feeding shaft. As a result, in the re-conveyance of the recording medium executed after the conveyance of the recording medium is stopped, it is possible to appropriately convey the recording medium while supporting the recording medium by the feeding shaft.

  Further, the printing apparatus may be configured such that the tension of the recording medium supported by the support unit after performing the first tension control is greater than the tension of the recording medium supported by the feeding shaft after performing the first tension control. good. With this configuration, a certain amount of tension is applied to the recording medium supported by the support unit even after the execution of the first tension control. Therefore, it is possible to prevent the recording medium from floating from the support portion and coming into contact with the printing portion due to the decrease in tension.

  Further, the printing apparatus may be configured to change the tension of the recording medium after the first tension control is executed according to the type of the recording medium. Thereby, appropriate tension control according to the type of the recording medium can be executed.

  Further, the printing apparatus may be configured such that the predetermined period is 200 seconds or more. By thus securing the predetermined period for a long time, it is possible to more reliably convey the recording medium properly in the re-conveyance of the recording medium performed after the conveyance of the recording medium is stopped.

  Further, the printing apparatus may be configured such that the predetermined period is 400 seconds or less. Accordingly, it is possible to suppress the recording medium from being stretched due to a large tension being applied to the stopped recording medium for a long time.

  In addition, the control unit may configure the printing apparatus to change the predetermined period according to an input operation to the input unit. Thus, the predetermined period can be set according to the needs of the user.

  Note that all of the plurality of components included in each embodiment of the present invention described above are not essential, and some or all of the effects described in this specification are solved in order to solve some or all of the above-described problems. Or, in order to achieve all of them, it is possible to appropriately change, delete, replace with some other constituent elements, and partially delete limited contents, some of the plurality of constituent elements. is there. In addition, in order to solve some or all of the above problems or to achieve some or all of the effects described in this specification, technical features included in one embodiment of the present invention described above are described. Some or all of the technical features included in other aspects of the present invention described above may be combined with some or all of the technical features to form an independent aspect of the present invention.

FIG. 1 is a front view schematically illustrating an example of a device configuration of a printer to which the invention is applied. FIG. 2 is a block diagram showing an electrical configuration for controlling the printer shown in FIG. 1. 5 is a flowchart illustrating an example of web tension control. 4 is a chart showing an example of an operation executed according to the flowchart of FIG. The figure which shows the specific example of web tension control in a table form.

  FIG. 1 is a front view schematically showing an example of a device configuration of a printer to which the present invention is applied. As shown in FIG. 1, in the printer 1, a single web S whose both ends are wound around a feeding shaft 20 and a winding shaft 40 in a roll shape is stretched along a transport path. Printing is performed while being transported in the transport direction Ds from the feeding shaft 20 to the winding shaft 40. The types of the web S are roughly classified into a paper type and a film type. As specific examples, the paper system includes high-quality paper, cast paper, art paper, and coated paper, and the film system includes synthetic paper, PET (Polyethylene terephthalate), PP (polypropylene), and the like. Schematically, the printer 1 includes a feeding section 2 (feeding area) for feeding the web S from the feeding shaft 20, a processing section 3 (process area) for printing an image on the web S fed from the feeding section 2, and a process. A winding section 4 (winding area) for winding the web S on which an image is printed by the section 3 onto a winding shaft 40; In the following description, of the two surfaces of the web S, the surface on which an image is printed is referred to as a front surface, and the opposite surface is referred to as a back surface.

  The feeding portion 2 includes a feeding shaft 20 around which the end of the web S is wound, and a driven roller 21 around which the web S drawn from the feeding shaft 20 is wound. The feeding shaft 20 winds and supports the end of the web S with the surface of the web S facing outward. Then, the web S wound around the feeding shaft 20 is fed to the process unit 3 via the driven roller 21 by the clockwise rotation of the feeding shaft 20 in FIG. Incidentally, the web S is wound around the pay-out shaft 20 via a core tube 22 that is detachable from the pay-out shaft 20. Therefore, when the web S of the feeding shaft 20 is used up, a new core tube 22 around which the rolled web S is wound can be mounted on the feeding shaft 20 and the web S of the feeding shaft 20 can be replaced. It has become.

  The feeding shaft 20 and the driven roller 21 can move in a width direction (a direction perpendicular to the paper surface of FIG. 1) orthogonal to the transport direction Ds, and the feeding portion 2 moves the positions of the feeding shaft 20 and the driven roller 21. It has a steering mechanism 23 that adjusts in the width direction (axial direction) to suppress meandering of the web S. The steering mechanism 23 includes an edge sensor 231 and a width direction driving unit 232. The edge sensor 231 is provided on the downstream side of the driven roller 21 in the transport direction Ds, facing the edge of the web S in the width direction, and detects the position of the edge of the web S in the width direction. In addition, the width direction drive unit 232 moves the feeding shaft 20 and the driven roller 21 in the width direction according to the detection result of the edge sensor 231. Thus, the meandering of the web S is suppressed.

  The process unit 3 performs processing by the functional units 51, 52, 61, 62, and 63 arranged along the outer peripheral surface of the rotary drum 30 while supporting the web S fed from the feed unit 2 by the rotary drum 30. The image is recorded on the web S as appropriate. In the process unit 3, a front driving roller 31 and a rear driving roller 32 are provided on both sides of the rotating drum 30, and the web S conveyed from the front driving roller 31 to the rear driving roller 32 in the conveyance direction Ds. Are supported by the rotating drum 30 and receive printing.

  The front drive roller 31 has a plurality of fine protrusions formed by thermal spraying on the outer peripheral surface, and winds the web S fed from the feeding portion 2 from the back side. Then, the front drive roller 31 rotates clockwise in FIG. 1 to transport the web S fed from the feeding unit 2 to the downstream side in the transport direction Ds. Note that a nip roller 31n is provided for the front drive roller 31. The nip roller 31 n is in contact with the surface of the web S while being urged toward the front drive roller 31, and sandwiches the web S with the front drive roller 31. Thereby, the frictional force between the front driving roller 31 and the web S is ensured, and the conveyance of the web S by the front driving roller 31 can be reliably performed.

  The rotating drum 30 is a cylindrical drum having a diameter of, for example, 400 [mm] and rotatably supported in both the transport direction Ds and the opposite direction by a support mechanism (not shown). The web S conveyed to the driving roller 32 is wound from the back side. The rotating drum 30 receives the frictional force between the web S and the web S and rotates in the transport direction Ds of the web S to support the web S from the back side. Incidentally, the process unit 3 is provided with driven rollers 33 and 34 that fold the web S on both sides of the winding unit around the rotating drum 30. The driven roller 33 wraps the surface of the web S between the front drive roller 31 and the rotating drum 30 and turns the web S back. On the other hand, the driven roller 34 wraps the surface of the web S between the rotating drum 30 and the rear drive roller 32, and turns the web S back. In this way, by folding back the web S on the upper and lower sides of the rotating drum 30 in the transport direction Ds, a long winding portion of the web S around the rotating drum 30 can be secured.

  The rear drive roller 32 has a plurality of minute projections formed by thermal spraying on the outer peripheral surface, and winds the web S conveyed from the rotary drum 30 via the driven roller 34 from the back side. The rear drive roller 32 conveys the web S to the winding unit 4 by rotating clockwise in FIG. Note that a nip roller 32n is provided for the rear drive roller 32. The nip roller 32 n is in contact with the surface of the web S while being urged toward the rear drive roller 32, and sandwiches the web S between the nip roller 32 n and the rear drive roller 32. Thereby, the frictional force between the rear drive roller 32 and the web S is ensured, and the conveyance of the web S by the rear drive roller 32 can be reliably performed.

  Thus, the web S conveyed from the front drive roller 31 to the rear drive roller 32 is supported on the outer peripheral surface of the rotating drum 30. In the process section 3, a plurality of recording heads 51 corresponding to different colors are provided in order to record a color image on the surface of the web S supported by the rotating drum 30. Specifically, four print heads 51 corresponding to yellow, cyan, magenta, and black are arranged in the transport direction Ds in this color order. Each recording head 51 faces the surface of the web S wound around the rotary drum 30 with a slight clearance, and discharges ink of a corresponding color (colored ink) from a nozzle by an ink jet method. Then, each recording head 51 ejects ink to the web S conveyed in the conveyance direction Ds, so that a color image is formed on the surface of the web S.

  Further, as the ink, UV (ultraviolet) ink (photo-curable ink) that is cured by irradiating ultraviolet rays (light) is used. Therefore, in the process unit 3, UV irradiators 61 and 62 (light irradiating units) are provided in order to cure the ink and fix it to the web S. The ink curing is performed in two stages, that is, temporary curing and main curing. A UV irradiator 61 for temporary curing is arranged between each of the plurality of recording heads 51. That is, the UV irradiator 61 cures (temporarily cures) the ink by irradiating it with ultraviolet light having a weak irradiation intensity to such an extent that the wetting and spreading of the ink becomes sufficiently slower than when the ultraviolet light is not irradiated. It does not fully cure the ink. On the other hand, a UV irradiator 62 for main curing is provided downstream of the plurality of recording heads 51 in the transport direction Ds. In other words, the UV irradiator 62 irradiates ultraviolet rays having a higher irradiation intensity than the UV irradiator 61 to cure (mainly cure) the ink to such an extent that the spread of the ink stops.

  In this manner, the UV irradiator 61 disposed between each of the plurality of recording heads 51 temporarily cures the colored ink discharged from the recording head 51 on the upstream side in the transport direction Ds onto the web S. Accordingly, the ink ejected onto the web S by one recording head 51 is temporarily cured by the time the recording head 51 adjacent to the one recording head 51 is located downstream in the transport direction Ds. This suppresses the occurrence of color mixing such as mixing of colored inks of different colors. In this state where the color mixture is suppressed, the plurality of recording heads 51 eject color inks of different colors from each other to form a color image on the web S. Further, a UV irradiator 62 for main curing is provided downstream of the plurality of recording heads 51 in the transport direction Ds. Therefore, the color image formed by the plurality of recording heads 51 is fully cured by the UV irradiator 62 and fixed to the web S.

  Further, a recording head 52 is provided downstream of the UV irradiator 62 in the transport direction Ds. The recording head 52 is opposed to the surface of the web S wound around the rotary drum 30 with a slight clearance, and discharges transparent UV ink from the nozzles onto the surface of the web S by an inkjet method. That is, the transparent ink is further ejected to the color images formed by the recording heads 51 for the four colors. This transparent ink is ejected over the entire surface of the color image to give the color image a texture such as glossiness or matteness. A UV irradiator 63 is provided downstream of the recording head 52 in the transport direction Ds. The UV irradiator 63 irradiates strong ultraviolet rays to fully cure the transparent ink discharged from the recording head 52. Thereby, the transparent ink can be fixed on the surface of the web S.

  As described above, in the processing unit 3, the ejection and curing of the ink are appropriately performed on the web S wound around the outer peripheral portion of the rotating drum 30, and a color image coated with the transparent ink is formed. Then, the web S on which the color image is formed is transported to the winding unit 4 by the rear drive roller 32.

  The winding unit 4 has, in addition to the winding shaft 40 around which the end of the web S is wound, a driven roller 41 that winds the web S between the winding shaft 40 and the rear drive roller 32 from the back surface side. The winding shaft 40 winds and supports the end of the web S with the surface of the web S facing outward. That is, when the take-up shaft 40 rotates clockwise in FIG. 1, the web S transported from the rear drive roller 32 is taken up by the take-up shaft 40 via the driven roller 41. Incidentally, the web S is wound on the winding shaft 40 via a core tube 42 that is detachable from the winding shaft 40. Therefore, when the web S wound around the winding shaft 40 becomes full, the web S can be removed together with the core tube 42.

  The outline of the device configuration of the printer 1 has been described above. Next, an electrical configuration for controlling the printer 1 will be described. FIG. 2 is a block diagram showing an electrical configuration for controlling the printer shown in FIG. As shown in FIG. 2, the printer 1 is provided with a printer control unit 100 that performs a function of totally controlling each unit of the apparatus. The printer control unit 100 is a computer including a CPU (Central Processing Unit) and a RAM (Random Access Memory).

  Further, the printer 1 is provided with a user interface 200 that functions as an interface between the printer control unit 100 and a user. The user interface 200 includes input devices such as a mouse and a keyboard, and output devices such as a display. Therefore, the user can input a desired command to the printer control unit 100 by operating the input device of the user interface 200, and can check the operation status of the printer 1 by checking the output device of the user interface 200. Note that the input device and the output device do not need to be configured separately, and they may be integrally configured by a touch panel display or the like.

  The printer control unit 100 controls each unit of the recording head, the UV irradiator, and the web transport system based on a command input by a user via the user interface 200 or a command received from another external device. Details of such control are as follows.

  The printer control unit 100 controls the ink ejection timing of each recording head 51 that forms a color image according to the conveyance of the web S. Specifically, the control of the ink ejection timing is executed based on an output (detection value) of a drum encoder E30 that is attached to the rotation shaft of the rotation drum 30 and detects the rotation position of the rotation drum 30. That is, since the rotating drum 30 is driven to rotate with the transport of the web S, the transport position of the web S can be grasped by referring to the output of the drum encoder E30 that detects the rotational position of the rotating drum 30. Therefore, the printer control unit 100 generates a pts (print timing signal) signal from the output of the drum encoder E30, and controls the ink ejection timing of each recording head 51 based on the pts signal. The ejected ink lands on a target position of the transported web S to form a color image.

  The timing at which the recording head 52 ejects the transparent ink is also controlled by the printer control unit 100 based on the output of the drum encoder E30. Thereby, the transparent ink can be accurately ejected to the color image formed by the plurality of recording heads 51. Further, the timing of turning on / off the UV irradiators 61, 62, 63 and the irradiation light amount are also controlled by the printer control unit 100.

  Further, the printer control unit 100 controls a function of controlling the conveyance of the web S described in detail with reference to FIG. The transport control of the web S mainly includes the steering control and the tension control of the web S. The steering control is executed using a steering mechanism 23 provided in the feeding section 2. That is, the printer control unit 100 adjusts the position of the feeding shaft 20 and the driven roller 21 in the width direction by the width direction driving unit 232 according to the detection result of the edge sensor 231, and thereby the position of the web S in the width direction. Feedback control. The tension control is performed using a motor connected to the feeding shaft 20, the front driving roller 31, the rear driving roller 32, and the winding shaft 40 among the members constituting the web transport system. The details of the tension control of the web S are as follows.

  The printer control unit 100 supplies the web S from the feeding shaft 20 to the front driving roller 31 by rotating a feeding motor M20 that drives the feeding shaft 20 by a direct drive method. At this time, the printer control unit 100 controls the torque of the feeding motor M20 to adjust the tension of the web S from the feeding shaft 20 to the front drive roller 31 (feeding tension Ta). That is, a tension sensor S21 that detects the magnitude of the feeding tension Ta is attached to the driven roller 21 disposed between the feeding shaft 20 and the front driving roller 31. The tension sensor S21 can be constituted by, for example, a load cell that detects the magnitude of a force received from the web S. Then, based on the detection result (detected value) of the tension sensor S21, the printer control unit 100 performs feedback control of the torque of the feeding motor M20 to adjust the feeding tension Ta of the web S.

  Further, the printer control unit 100 rotates a front drive motor M31 that drives the front drive roller 31 and a rear drive motor M32 that drives the rear drive roller 32. Thus, the web S fed from the feeding section 2 passes through the processing section 3. At this time, speed control is performed on the front drive motor M31, while torque control is performed on the rear drive motor M32. That is, the printer control unit 100 performs feedback control of the rotation speed of the front drive motor M31 based on the output of the encoder of the front drive motor M31. Thereby, the web S is conveyed by the front drive roller 31 at the target speed.

  On the other hand, the printer control unit 100 controls the torque of the rear drive motor M32 to adjust the tension of the web S from the front drive roller 31 to the rear drive roller 32 (process tension Tb). That is, the driven roller 34 disposed between the rotary drum 30 and the rear drive roller 32 is provided with the tension sensor S34 for detecting the magnitude of the process tension Tb. The tension sensor S34 can be constituted by, for example, a load cell that detects the magnitude of a force received from the web S. Then, based on the detection result (detected value) of the tension sensor S34, the printer control unit 100 performs feedback control of the torque of the rear drive motor M32 to adjust the process tension Tb of the web S.

  Further, the printer control unit 100 rotates the winding motor M40 that drives the winding shaft 40 by a direct drive method, and winds the web S transported by the rear drive roller 32 around the winding shaft 40. At this time, the printer control unit 100 controls the torque of the winding motor M40 to adjust the tension of the web S from the rear drive roller 32 to the winding shaft 40 (winding tension Tc). That is, the driven roller 41 disposed between the rear drive roller 32 and the winding shaft 40 is provided with the tension sensor S41 for detecting the magnitude of the winding tension Tc. The tension sensor S41 can be constituted by, for example, a load cell that detects the magnitude of a force received from the web S. Then, based on the detection result (detected value) of the tension sensor S41, the printer control unit 100 performs feedback control of the torque of the winding motor M40 to adjust the winding tension Tc of the web S.

  In particular, the printer control unit 100 adjusts each of the tensions Ta, Tb, and Tc to the printing tensions Ta1, Tb1, and Tc1 during the transport period in which the web S is transported along with the execution of the printing operation, and executes the printing operation. During the standby period in which the transport of the web S is stopped without performing the operation, the tensions Ta, Tb, and Tc are adjusted to the standby tensions Ta2, Tb2, and Tc2. Here, the standby tensions Ta2, Tb2, Tc2 are respectively lower than the printing tensions Ta1, Tb1, Tc1 (Ta2 <Ta1, Tb2 <Tb1, Tc2 <Tc1). In addition, the printing tensions Ta1, Tb1, and Tc1 can be said to be transport tensions necessary for properly transporting the web S. Subsequently, the tension control will be described in detail.

  FIG. 3 is a flowchart showing an example of web tension control. This flowchart is executed by the printer control unit 100. In step S101, it is determined whether to start a printing operation for printing an image on the web S while transporting the web S in the transport direction Ds. When it is determined that the printing operation is started (“YES” in step S101), the tensions Ta, Tb, and Tc of the web S are increased from the standby tensions Ta2, Tb2, and Tc2 to the printing tensions Ta1, Tb1, and Tc1. (Step S102). Subsequently, the transport of the web S in the transport direction Ds is started (Step S103), and the printing operation is performed (Step S104). When the printing operation is completed (Step S105), a stop operation for stopping the conveyance of the web S in the conveyance direction Ds is performed (Step S106).

  In step S107, counting for measuring the elapsed time from the stop operation is started. In step S108, it is determined whether the count value has become equal to or greater than a predetermined count value, that is, whether a predetermined period (for example, 300 seconds) has elapsed since the stop operation. It is confirmed. If the count value is less than the predetermined count value ("NO" in step S108), it is confirmed whether or not the user has input a transfer command via the user interface 200 (step S109). If the transfer command has not been input ("NO" in step S109), the process returns to step S108.

  On the other hand, if a transport command is input ("YES" in step S109), a transport operation for transporting web S is performed (step S110). The transport commands that can be input to the user interface 200 include a forward transport command for instructing execution of forward transport for transporting the web S in the transport direction Ds, and a reverse transport for transporting the web S in the reverse direction of the transport direction Ds. There is a reverse transport command for instructing execution. Therefore, in step S110, forward conveyance or reverse conveyance is executed according to the contents of the conveyance command input by the user. Then, when the end of the transport operation is confirmed in step S111 (“YES” in step S111), the process returns to step S108.

  If it is determined in step S108 that the count value has become equal to or greater than the predetermined count value, that is, "YES", the count is reset (step S112), and the tensions Ta, Tb, and Tc of the web S are changed to the print tension Ta1. , Tb1, Tc1 to standby tensions Ta2, Tb2, Tc2 (step S102). Then, the process returns to step S101.

  FIG. 4 is a timing chart showing an example of the operation executed according to the flowchart of FIG. The upper graph of FIG. 4 shows the time change of the transport speed of the web S, the middle graph of FIG. 4 shows the time change of the tension of the web S, and the lower graph of FIG. This shows the time change of the trigger. As described above, the tension of the web S includes the feeding tension Ta, the process tension Tb, and the winding tension Tc. However, the qualitative changes of the feeding tensions Ta, Tb, and Tc are the same, and are shown in FIG. 4 without distinction.

  Prior to the start of the printing operation, when the trigger switches from off to on at time t1, the tension of the web S starts to increase from the standby tension and becomes the printing tension at time t2. At this time, the tension switching time Δt12 required for switching the tension of the web S can be set to, for example, 10 seconds. Subsequently, the acceleration of the web S is started at time t3, and the transport speed of the web S reaches the printing speed at time t4. At this time, the acceleration time Δt34 required to accelerate the speed of the web S to the printing speed is shorter than the tension switching time Δt12, and can be set to, for example, 2.5 seconds. Then, the printing operation is started in a state where the web S is transported at a constant speed at the printing speed.

  When the printing operation ends, the deceleration of the web S in the transport direction Ds starts at time t5, and the transport of the web S stops at time t6 (stop operation). At this time, the deceleration time Δt56 required to decelerate the web S is shorter than the tension switching time Δt12, and can be set to, for example, 2.5 seconds. Subsequently, when the trigger is switched from on to off at a time t7 when a predetermined period P has elapsed from the time t6 when the stop operation has ended, the tension of the web S starts to decrease from the print tension and becomes a standby tension at a time t8. . At this time, the tension switching time Δt78 required for switching the tension of the web S is equal to the tension switching time Δt12, and can be set to, for example, 10 seconds.

  As described above, in the present embodiment, a printing operation for printing an image on the web S while the web S is being transported in the transport direction Ds is performed, and the transport of the web S is stopped according to the end of the printing operation. A stop operation is performed. Further, the tension of the web S is kept constant from the execution of the printing operation until the predetermined period P has elapsed from the stop operation, and the tension of the web S is reduced after the predetermined period P has elapsed from the stop operation. (First tension control). That is, the tension of the web S is not immediately reduced when the conveyance of the web S is stopped, but the tension of the web S is maintained at the printing tension for a predetermined period P from the stop of the conveyance of the web S. Accordingly, if the timing at which the user inputs the transport command for re-transporting the web S is within the predetermined period P, the re-transportation of the web S can be executed with an appropriate tension applied to the web S. . As a result, in the re-transportation of the web S performed after the transport of the web S is stopped, the web S can be properly transported.

  When the predetermined period P has elapsed without input of a transport command from the user, the tension of the web S is reduced to the standby tension. Thereby, it is possible to suppress the web S from being stretched due to the large tension being applied to the stopped web S for a long time. In addition, since the power consumed by each of the motors M20, M32, and M40 can be suppressed, the consumption of energy can be suppressed.

  Incidentally, various reasons can be assumed for the user to re-convey the web S. For example, in order to check the image printed on the web S, a case where the web S is transported backward until the image printed on the web S comes to a position where the image can be visually recognized can be assumed. The position where the image can be visually recognized is, for example, a position where the surface of the web S can be visually recognized from the opening of the door that opens and closes the housing of the printer 1. At this time, when the printer 1 is provided with a configuration in which the recording heads 51 and 52 and the UV irradiators 61, 62 and 63 can be integrally moved in the width direction and retracted from the surface of the rotary drum 30, The surface can be used as the corresponding position.

  Alternatively, a case where the web S wound around the winding shaft 40 is removed can be assumed. In this case, the user causes the printer 1 to execute the forward conveyance, winds the web S on which the image is printed on the winding shaft 40, and cuts the web S, thereby winding the web S on which the image is printed. It can be removed from the take-up shaft 40.

  In addition, the printer control unit 100 executes the first tension control on the web S supported on the rotating drum 30 by adjusting the torque of the rear drive roller 32. With such a configuration, the web S can be re-transported while the printing tension Tb1 is applied to the web S supported by the rotating drum 30. As a result, in the re-transportation of the web S performed after the transport of the web S is stopped, the web S can be appropriately transported while being supported by the rotating drum 30.

  In addition, the printer control unit 100 executes the first tension control on the web S supported by the winding shaft 40 by adjusting the torque of the winding shaft 40. With this configuration, the web S can be re-transported while the printing tension Tc1 is applied to the web S supported by the winding shaft 40. As a result, in the web S executed after the stop of the transport of the web S, the web S can be appropriately transported while being supported by the winding shaft 40.

  Further, the printer control unit 100 executes the first tension control on the web S supported by the feeding shaft 20 by adjusting the torque of the feeding shaft 20. With such a configuration, the web S can be re-transported while the printing tension Ta1 is applied to the web S supported by the feeding shaft 20. As a result, in the re-transportation of the web S performed after the transport stop of the web S, the web S can be appropriately transported while being supported by the feeding shaft 20.

  Further, the predetermined period P is set to 200 seconds or more. By securing the predetermined period P long as described above, the user can surely input a transfer command for instructing re-conveyance within the predetermined period P. As a result, in the re-transport of the web S performed after the stop of the transport of the web S, the web S can be transported more appropriately.

  Further, the predetermined period is set to 400 seconds or less. Thereby, it is possible to suppress the web S from being stretched due to the large tension being applied to the stopped web S for a long time. In addition, since the power consumed by each of the motors M20, M32, and M40 can be suppressed, the consumption of energy can be suppressed.

  As described above, in the above embodiment, the printer 1 corresponds to an example of the “printing device” of the present invention, and the feeding shaft 20, the front driving roller 31, the rotating drum 30, the rear driving roller 32, and the winding shaft 40 cooperate. The recording heads 51 and 52 correspond to an example of the printing unit “printing unit” of the present invention, and the user interface 200 functions as an example of the “input unit” of the present invention. , The printer control unit 100 corresponds to an example of the “control unit” of the present invention, the web S corresponds to an example of the “recording medium” of the present invention, and the web S is printed along with the printing operation in step S104. The carrying operation corresponds to an example of the “first carrying operation” of the present invention, the printing operation performed in step S104 corresponds to an example of the “printing operation” of the present invention, and the stopping operation performed in step S106 corresponds to In the present invention, The transport operation performed in step S110 corresponds to an example of the “second transport operation” of the present invention, and the tension control performed from time t6 to t8 in FIG. The rear drive roller 32 corresponds to an example of the “drive roller” of the present invention, the rotating drum 30 corresponds to an example of the “support portion” of the present invention, and the winding shaft corresponds to an example of “first tension control”. Reference numeral 40 corresponds to an example of the “winding shaft” of the present invention, and the feeding shaft 20 corresponds to an example of the “feeding shaft” of the present invention.

  The present invention is not limited to the above embodiment, and various changes can be made to the above described one without departing from the gist of the invention. Therefore, for example, as shown in FIG. 5, the content of the tension control can be changed depending on the type and width of the web S, or the content of the tension control can be changed depending on the areas such as the feeding unit 2, the process unit 3, and the winding unit 4. .

  FIG. 5 is a diagram showing a specific example of web tension control in a table format. In the figure, “F + paper” indicates the type of web S in which paper is laminated on a film, “F + F” indicates the type of web S in which a film is laminated on a film, and “width” is The width of the web S is shown. The numerical value shown in the “printing” line indicates the size of the corresponding printing tension, and the numerical value shown in the “standby” line indicates the size of the standby tension.

  In the example shown in the figure, the printer control unit 100 keeps the tension of the web S constant from the execution of the previous printing operation until the next printing operation is started after the previous printing operation is completed. The second tension control to be performed and the first tension control described above are selectively executed. That is, tension control for the feeding unit 2 and the winding unit 4 when the type of the web S is “F + F”, and feeding when the type of the web S is “F + paper” and the width of the web S is 80 mm to 160 mm. The tension control for the shaft 20 is a second tension control. According to the second tension control, the tension of the web S is maintained constant throughout the period in which the printing operation is being performed and the period in which the printing operation is not being performed, and the printing tension is equal to the standby tension. Even in such a second tension control, the web S can be re-transported with an appropriate tension applied to the web S. Therefore, in the re-transport of the web S performed after the stop of the transport of the web S, the web S can be appropriately transported.

  In particular, according to FIG. 5, the printer control unit 100 executes the first tension control when the magnitude of the tension applied to the web S at the time of performing the printing operation is equal to or greater than the predetermined tension (30N), and performs the first tension control at the time of performing the printing operation. When the magnitude of the tension applied to the web S is smaller than the predetermined tension (30N), the second tension control is executed. Thereby, the web S can be suppressed from being stretched due to the large tension greater than or equal to the predetermined tension being applied to the stopped web S for a long time. In addition, since the power consumed by each of the motors M20, M32, and M40 can be suppressed, the consumption of energy can be suppressed.

  Further, the printer control unit 100 appropriately determines which of the first tension control and the second tension control is to be executed according to the type of the web S. For example, the first tension control and the second tension control depending on the type of the web S are selectively used for the winding unit 4 and the feeding unit 2 when the width of the web S is wider than a predetermined width (200 mm to 340 mm). Specifically, when the type of the web S is “F + paper”, the first tension control is executed, and when the type of the web S is “F + F”, the second tension control is executed. Thus, the appropriate tension control according to the type of the web S is performed.

  Further, the printer control unit 100 appropriately determines which of the first tension control and the second tension control is to be executed according to the width of the web S. For example, for the feeding section 2 in the case where the web type is “F + paper”, the first and second tensions are selectively used according to the width of the web S. Specifically, when the width of the web S is wider than a predetermined value (200 mm to 340 mm), the first tension control is performed. When the width of the web S is narrower than a predetermined value (80 mm to 160 mm), the second tension control is performed. Is executed. Thus, appropriate tension control according to the width of the web S is performed.

  Further, the tension of the web S supported by the rotating drum 30 after the first tension control is performed (the standby tension of the process unit 3) is the web supported by the winding shaft 40 or the feeding shaft 20 after the first tension control is performed. It is larger than the tension of S (that is, the standby tension of the winding unit 4 or the feeding unit 2). With this configuration, a certain amount of tension is applied to the web S supported by the rotating drum 30 even after the execution of the first tension control. Therefore, it is possible to prevent the web S from floating from the rotary drum 30 and coming into contact with the recording heads 51 and 52 due to the decrease in tension.

  Further, various changes other than the contents shown in the specific example of FIG. 5 can be made. Therefore, for example, the tension of the web S after performing the first tension control may be changed according to the type of the web S. Thus, appropriate tension control according to the type of the web S can be performed.

  Further, the printer control unit 100 may configure the printer 1 to change the predetermined period P in accordance with an input operation to the user interface 200. In such a configuration, the user can appropriately change the predetermined period P according to his / her work habits and the like, and can set the predetermined period P according to the user's needs.

  Further, the timing at which the first tension control is performed is not limited to the timing at which the conveyance of the web S accompanying the printing operation is stopped. Therefore, the first tension control may be executed at the timing when the conveyance of the web S by the conveyance operation performed in response to the input of the conveyance command to the user interface 200 is stopped. That is, the first tension control can be performed each time the transfer operation is performed according to the transfer command from the user. In this case, of the two transport operations performed consecutively, the first transport operation corresponds to an example of the “first transport operation” of the present invention, and the next transport operation corresponds to the “second transport operation” of the present invention. ".

  In the above-described embodiment, a case where a transport command is input to the user interface 200 after the predetermined period P has elapsed is also assumed. In such a case, the conveyance may be started after the tension of the web S is increased from the standby tension to the printing tension.

  In the above example, the printer 1 supporting the web S by the rotating drum 30 has been described. However, the support mode of the web S is not limited to this, and the web S can be supported by a flat platen.

  DESCRIPTION OF SYMBOLS 1 ... Printer, 20 ... Feeding shaft, 31 ... Front drive roller, 30 ... Rotary drum, 32 ... Rear drive roller, 40 ... Winding shaft, 51, 52 ... Recording head, 100 ... Printer control part, 200 ... User interface, S: Web, S101 to S113: Steps executed by web tension control

Claims (15)

A transport unit that transports the recording medium while applying tension to the recording medium,
A printing unit that prints an image on the recording medium,
An input unit for inputting a transport command,
A first transport operation for transporting the recording medium by the transport unit, a stop operation for stopping the transport of the recording medium to the transport unit and terminating the first transport operation, and the transport instruction after the stop operation. A control unit capable of executing a second transport operation of transporting the recording medium by the transport unit when input to the input unit,
Wherein the control unit is configured from stop operation until the first hour has elapsed to maintain a constant tension of the recording medium continuously from the time of execution of the first transporting operation, elapses the first hour from the stop operation Then, a first tension control for reducing the tension of the recording medium, and from the end of the previous printing operation to the start of the next printing operation, from the time of execution of the previous printing operation. a second tension control for maintaining the tension of the recording medium constant, is selectively feasible, and, printing which prints an image on the recording medium by the printing unit while conveying the recording medium by the conveying unit Performing the first transport operation to perform an operation, performing the stop operation to terminate the first transport operation in response to the end of the printing operation, and performing the first tension control in the first tension control. Until the first time elapses from the stop operation, the tension of the recording medium is kept constant from the execution of the printing operation, and the tension of the recording medium is maintained after the first time elapses from the stop operation. A printing device that reduces tension . The controller executes the first tension control when the magnitude of the tension applied to the recording medium at the time of performing the printing operation is equal to or greater than a predetermined tension, and controls the tension applied to the recording medium at the time of performing the printing operation. The printing apparatus according to claim 1 , wherein the second tension control is performed when the size is smaller than the predetermined tension. Wherein the control unit, the printing apparatus according to either perform one of the first tension control and the second tension control in claim 1 or 2 is determined in accordance with the type of the recording medium. Wherein the control unit, the printing apparatus according to any one of claims 1 to 3 determining in accordance with whether to perform one of the first tension control and the second tension control on the width of the recording medium. The transport unit has a driving roller that drives the recording medium, and a support unit that is arranged to face the printing unit and supports the recording medium that is driven by the driving roller, and is supported by the support unit. Giving a tension to the recording medium by the torque of the drive roller,
Wherein, by adjusting the torque of the drive roller, in any one of from the support portion claims 1 capable of executing the first tension control on the recording medium which is supported by the 4 The printing device according to the above. The transport unit has a winding shaft that winds the recording medium printed by the printing unit, and applies tension to the recording medium wound around the winding shaft by a torque of the winding shaft.
The printing apparatus according to claim 5 , wherein the control unit is capable of executing the first tension control on the recording medium supported by the winding shaft by adjusting a torque of the winding shaft. Tension of the recording medium supported by the supporting portion after executing the first tension control, according to the tension larger claim 6 of the recording medium which is supported by the winding shaft after performing said first tension control Printing equipment. The transport unit has a pay-out shaft that feeds out the recording medium to the printing unit, and applies tension to the recording medium that is fed out from the feed-out shaft by a torque of the feed-out shaft,
Wherein the control unit is configured by adjusting the torque of the feeding shaft, in any one of the recording to claims 5 and can execute the first tension control to the medium 7 to be supported by the feeding shaft The printing device according to the above. Tension of the recording medium supported by the supporting portion after executing the first tension control, according to the tension larger claim 8 of the recording medium which is supported by the feed-out shaft after performing said first tension control Printing device. A transport unit that transports the recording medium while applying tension to the recording medium,
A printing unit that prints an image on the recording medium,
An input unit for inputting a transfer command,
A first transport operation for transporting the recording medium by the transport unit, a stop operation for stopping the transport of the recording medium to the transport unit and terminating the first transport operation, and the transport instruction after the stop operation. A control unit capable of executing a second conveyance operation of conveying the recording medium by the conveyance unit when input to the input unit;
With
The control unit keeps the tension of the recording medium constant from the execution of the first transport operation until the first time has elapsed from the stop operation, and the first time has elapsed since the stop operation. A printing apparatus that executes first tension control for reducing the tension of the recording medium and then changes the tension of the recording medium after the first tension control is executed according to the type of the recording medium. A transport unit that transports the recording medium while applying tension to the recording medium,
A printing unit that prints an image on the recording medium,
An input unit for inputting a transfer command,
A first transport operation for transporting the recording medium by the transport unit, a stop operation for stopping the transport of the recording medium to the transport unit and terminating the first transport operation, and the transport instruction after the stop operation. A control unit capable of executing a second conveyance operation of conveying the recording medium by the conveyance unit when input to the input unit;
With
The control unit keeps the tension of the recording medium constant from the execution of the first transport operation until a predetermined period has elapsed from the stop operation, and the predetermined period has elapsed since the stop operation. A first tension control for reducing the tension of the recording medium, and the recording medium continuously from the execution of the previous printing operation until the next printing operation is started after the previous printing operation is completed. And a second tension control for maintaining the tension of the recording medium constant, and a printing operation of printing an image on the recording medium by the printing unit while conveying the recording medium by the conveyance unit. Executing the first transport operation to perform the first transport operation, performing the stop operation to terminate the first transport operation in response to the end of the printing operation, Until the predetermined period elapses from the stop operation, the tension of the recording medium is maintained constant from the execution of the printing operation, and the tension of the recording medium is maintained after the predetermined period elapses from the stop operation. Decrease
The printing apparatus , wherein the predetermined period is 200 seconds or more and 400 seconds or less . A transport unit that transports the recording medium while applying tension to the recording medium,
A printing unit that prints an image on the recording medium,
An input unit for inputting a transport command,
A first transport operation for transporting the recording medium by the transport unit, a stop operation for stopping the transport of the recording medium to the transport unit and terminating the first transport operation, and the transport instruction after the stop operation. A control unit capable of executing a second conveyance operation of conveying the recording medium by the conveyance unit when input to the input unit;
With
The control unit keeps the tension of the recording medium constant from the execution of the first transport operation until a predetermined period has elapsed from the stop operation, and the predetermined period has elapsed since the stop operation. Performing a first tension control to reduce the tension of the recording medium from, changing the tension of the recording medium after performing the first tension control according to the type of the recording medium,
The printing device , wherein the predetermined period is 200 seconds or more and 400 seconds or less. Wherein the control unit, the printing apparatus according to any one of claims 1 to 10 to change the first hour in response to the input operation to the input unit.   The printing apparatus according to claim 11, wherein the control unit changes the predetermined period according to an input operation on the input unit. Performing a first transport operation for transporting the recording medium;
Performing a stop operation for stopping conveyance of the recording medium and terminating the first conveyance operation;
Performing a second transport operation for transporting the recording medium when a transport command is input after the stop operation,
Until the first time elapses from the stop operation, the tension of the recording medium is maintained constant from the execution of the first transport operation, and the recording is performed after the first time elapses from the stop operation. Reduce media tension ,
Wherein the tension of the first hour the recording medium after the lapse, tension control method Ru vary depending on the type of the recording medium.

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